编写Java程序，实现以下功能：判断两个字符串是否相同、判断字符串的前缀、后缀是否和某个字符串相同、按字典序比较两个字符串的大小关系、检索字符串、将数字串转换成数字、获取字符串的字符数组、获取字符串指定编码的字节数组、用字符数组创建字符串、用字节数组创建字符串。

import java.nio.charset.StandardCharsets;

public class StringDemo {

    public static void main(String[] args) {
        String str1 = "hello";
        String str2 = "world";
        String str3 = "hello world";
        String str4 = "hi";
        String str5 = "hello world";
        String str6 = "12345";
        String str7 = "中文";

        // 判断两个字符串是否相同
        boolean isEqual = str1.equals(str2);
        System.out.println("str1 equals str2: " + isEqual);

        isEqual = str3.equals(str5);
        System.out.println("str3 equals str5: " + isEqual);

        // 判断字符串的前缀、后缀是否和某个字符串相同
        boolean isStartsWith = str1.startsWith("he");
        System.out.println("str1 starts with 'he': " + isStartsWith);

        boolean isEndsWith = str2.endsWith("ld");
        System.out.println("str2 ends with 'ld': " + isEndsWith);

        // 按字典序比较两个字符串的大小关系
        int result = str1.compareTo(str2);
        System.out.println("str1 compareTo str2: " + result);

        result = str1.compareTo(str4);
        System.out.println("str1 compareTo str4: " + result);

        // 检索字符串
        int index = str3.indexOf("world");
        System.out.println("Index of 'world' in str3: " + index);

        index = str3.indexOf("java");
        System.out.println("Index of 'java' in str3: " + index);

        // 将数字串转换成数字
        int num = Integer.parseInt(str6);
        System.out.println("String to number: " + num);

        // 获取字符串的字符数组
        char[] charArray = str1.toCharArray();
        System.out.println("String to char array: " + new String(charArray));

        // 获取字符串指定编码的字节数组
        byte[] byteArray = str7.getBytes(StandardCharsets.UTF_8);
        System.out.println("String to byte array: " + new String(byteArray, StandardCharsets.UTF_8));

        // 用字符数组创建字符串
        String str8 = new String(new char[]{'h', 'e', 'l', 'l', 'o'});
        System.out.println("Char array to string: " + str8);

        // 用字节数组创建字符串
        String str9 = new String(new byte[]{104, 101, 108, 108, 111}, StandardCharsets.UTF_8);
        System.out.println("Byte array to string: " + str9);
    }
}